The present invention relates to a device and a method for testing the triggering characteristics of restraining devices in a motor vehicle, such as airbags and belt tighteners, in which the restraint devices are triggered via a control device.
In modern control devices of this kind, the triggering characteristics of the individual restraint devices installed in the motor vehicle do not only depend on the kind of acceleration to which the motor vehicle and thus the control device is exposed, but also on other status data, such as the speed of the motor vehicle, the position and possibly the weight class of the occupant(s), whether a child-seat is present or not, whether a belt lock is closed or not, etc. These status data are usually detected with the aid of suitable sensors as peripheral state and are transmitted to the control device, so that the instantaneous peripheral state may be taken into account when the individual restraint devices are triggered. Therefore, a multitude of different triggering situations result, given the variation possibilities in regard to equipping a motor vehicle with restraint devices.
In programming the control device, the restraint-device equipment of the motor vehicle desired by the customer is taken into account. The control-device software is usually implemented in a modular manner and testing is carried out during production in an artificial environment solely on a module-basis.
In practice, this method is problematic, not only because an ever increasing number of status data are to be considered in the triggering of the individual restraint devices, but also because the interaction occurring between the individual restraint devices also has to be taken into account. As the number of restraint systems increases, so does the importance of these interactions.
According to the present invention, a device and a method are provided that allow a systematic testing of the triggering characteristics of restraint devices in a motor vehicle under conditions that are as realistic as possible.
For that purpose, the device according to the present invention includes an ambiency simulator connectable to a control device for stipulating defined peripheral states, an acceleration device for accelerating the control device, detecting means for recording the triggering characteristics of the restraint device in response to the acceleration of the control device, and evaluation means for evaluating the recorded triggering characteristics.
In accordance with the method according to the present invention, the control device is first programmed for a particular constellation of restraint devices. With the aid of an ambiency simulator, a defined peripheral state is then stipulated for the control device. Next, the control device is accelerated, in this manner provoking a triggering of the restraint devices. The triggering characteristics of the restraint devices, given the current peripheral state, will then be recorded and evaluated.
It has been recognized that the interactions occurring between the individual restraint devices upon triggering may only be detected under actual load conditions, i.e., in actual acceleration of the control device and in actual activation of the restraint devices. Furthermore, it has become known that, in contrast to these interactions, the various peripheral states occurring in actuality may be simulated in a simple manner by providing the control device with appropriate status data. Therefore, it is provided in accordance with the present invention, to automatically and systematically test the triggering characteristics of the individual restraint devices of a motor vehicle, on the one hand, under actual load conditions, and in merely simulated peripheral states, on the other hand.
Basically, there are different possibilities for implementing the device or the method according to the present invention.
In an advantageous embodiment, the device according to the present invention includes a control-PC connected to the control device, which may be used to program the control device. In this manner, it is easy to predefine certain constellations of restraint devices, i.e. equipment variants, for the control device.
The control-PC may also be connected to the ambiency simulator, which is advantageous especially in view of an automatic and systematic stipulation of various defined peripheral states.
Finally, the control-PC could also be used in the evaluation of the recorded triggering characteristics.